normal fault

normal fault ( geological Engineering)

1. Outline: Outline: Normal Fault Systems and KinematicsNormal Fault Systems and Kinematics
• Planar Faults and Block Rotation
• Detachment Faulting
• Fault Linkage
• Kinematics of Normal Faulting

2. Development of Continental Rift into Ocean Basin
Upwelling of hot mantle
Thins, weakens, and
cracks the lithosphere

3. Development of Continental Rift into Ocean Basin
Rift Valley
Early graben formation
prior to continental
splitting. This stage
may be associated
with domal uplift
caused by uprise of hot
upper mantle material -
uplift may be
connected with
underlying mantle
hotspots.

4. Development of Continental Rift into Ocean Basin
Young ocean basin
Last about 50 my after the
onset of seafloor spreading,
while the thermal effects are
still dominant.
Characterized by rapid
regional subsidence of the
outer shelf and slope, but
some graben formation may
persist. Example: Red Sea.

5. Development of Continental Rift into Ocean Basin
Mature Ocean basin
Subdued regional
subsidence may continue.
Example: most of the
present Atlantic
continental margins.

6. East African Rift SegmentationEast African Rift Segmentation
9 mm/a (GPS)
16 mm/a (GPS)

10. Basin and Range Normal Fault BlocksBasin and Range Normal Fault Blocks

11. Rio Grande Rio Grande
RiftRift
Segmentation Segmentation

12. Death ValleyDeath Valley
Fault Zone Fault Zone
Fault StepoverFault Stepover

13. Closeup of StepoverCloseup of Stepover

14. Planar Normal Faults and Block RotationPlanar Normal Faults and Block Rotation

15. Planar Normal Faults and Block RotationPlanar Normal Faults and Block Rotation

16. Domino Block ExampleDomino Block Example

17. Domino Block ExampleDomino Block Example

18. Detachment FaultDetachment Fault

19. Detachment FaultDetachment Fault

20. Detachment FaultDetachment Fault

21. Soft-Linked SystemsSoft-Linked Systems

22. Kinematics of Normal FaultingKinematics of Normal Faulting
• Domino, Bookshelf-Style Normal Faulting
• Listric Normal Faulting with Reverse Drag
• Imbricate Listric Normal Faulting
• Inversion

23. Domino-Style Normal FaultingDomino-Style Normal Faulting

24. Domino-Style Normal Faulting (bookshelf faulting)Domino-Style Normal Faulting (bookshelf faulting)
Occurs above Detachment faultsOccurs above Detachment faults

25. Listric-Planar Normal Fault SystemListric-Planar Normal Fault System
???

26. Listric-Planar Normal Fault SystemListric-Planar Normal Fault System
L

27. Listric Normal Faulting with Reverse DragListric Normal Faulting with Reverse Drag

28. Listric Normal Faulting with RolloverListric Normal Faulting with Rollover
Occurs due to space problem with curved detachmentOccurs due to space problem with curved detachment

29. Imbricate Listric Normal FaultingImbricate Listric Normal Faulting
Synthetic faults also accommodate collapse of HW blockSynthetic faults also accommodate collapse of HW block

30. Imbricate Listric Normal FaultingImbricate Listric Normal Faulting
““Meatslices common in large displacement systemsMeatslices common in large displacement systems

31. InversionInversion
• Normal faulting
• Syn-tectonic deposition of B
• Post-tectonic deposition of C

32. InversionInversion
• Normal faulting
• Syn-tectonic deposition of B
• Post-tectonic deposition of C
• Thrust faulting
• Deformation of B and folding
of C

33. ReferencesReferences
Slides 1, 20, 21Slides 1, 20, 21
Twiss, R. J. and E. M. Moores, Structural Geology, W. H. Freeman & Co., New York, 532 p., Twiss, R. J. and E. M. Moores, Structural Geology, W. H. Freeman & Co., New York, 532 p.,
1992.1992.
Slides 3-6Slides 3-6
http://earth.http://earth.leedsleeds.ac..ac.uk/faults/normal/dominouk/faults/normal/domino..htmhtm
Slides 7-9Slides 7-9
http://earth.http://earth.leedsleeds.ac.uk/faults/normal/detachment1..ac.uk/faults/normal/detachment1.htmhtm
Slide 10Slide 10
http://earth.leeds.ac.uk/faults/soft/softnormal.http://earth.leeds.ac.uk/faults/soft/softnormal.htmhtm
Slides 12-19Slides 12-19
Davis. G. H. and S. J. Reynolds, Structural Geology of Rocks and Regions, 2nd ed., John Davis. G. H. and S. J. Reynolds, Structural Geology of Rocks and Regions, 2nd ed., John
Wiley & Sons, New York, 776 p., 1996.Wiley & Sons, New York, 776 p., 1996.